Improvement in the manufacture of zinc-white



N. BARTLETT. 1 Ma ufacture of Zinc-white."` 1 N0. 139,701. PatentedJune10.187f:l.\`

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AM PHara-L/Tf/osmm/c co. N1( osaafwf man s NATHAN BARTLETT, or BAYONNE UEL c. WEST, or ELIZABETH, NEW JERSEY.

UNITED STATES CITY, ASSIeNoE ToA PATENT OFFICE.

IMSELEANDSAM- i IMPROVEMENT IN THE MANUFACTURE OFZINC-WHITEQ.

Specification forming part of Letters Patent No. 139,701, dated June 10, 1873; application filed April 19, 1873.

. pointed out in the claims.

Figure 1 is a longitudinal sectional elevation of the aforesaid furnace constructed accordingto my improvements. Fig. 2 is a horizontal section, and Fig. 3 is a transverse sectional elevation.

Similar letters of reference indicate correspondin g parts.

The furnace has three chambers, an upper one, K, middle one, H, and lower one, L. The lire is built'at one end, B, and delivers `the lighter vapor into the upper chamber and the heavier into themiddle chamber, the latter vapor passing out at the` chimney J, while the former, after traversing the length of the furnace, descends in two passages, h3, to the lower chamber, Where, after having twice traversed the whole length, it enters the discharge-chimney M.

My improvement in the arrangement of the furnace consists in making the middle 'chamber H funnel-shaped, or approximately so, as represented in Figs. 1 and 2, by which to ecncentrate the heat, as before stated, and thus work out the oxide from the ore much cleaner than it has ever been done before, and thus increase the percentage of gain.

1n carrying out my improved mode of working the furnace, I have the chamber H in fo .1r imaginary sections, as indicated by the Figs. 1, 2, 3, and 4, and when fully heated'and charged I remove the batch 4 of the residuum at the opening O, shift the otherbatches along one stage, and apply a fresh batch at l, thus pipes P discharging into the chamber H at Q, so that the air, which isforcediu'by auysuitable blower, unites with the gases as they emerge from the passa-ges h2, and burns iutensely. 1 use cold air. By these im rove ments in the aforesaid furnace I save one-third ofthe fuel `heretofore used, als about half thelabor of working it, and secure suchv thorough reduction of the ores thatMthe amount of zinc lost is less than two per cent.

Having thus describedrmy invention, I claim as new and desire to secure by Letters Patentl. The chamber H, made `widest at the mouth `and tapering` tothe escape, as and fo the purpose described. 2. 'lhe mode ofworking zinc-oxide furnaces by supplying the ore at the frontfromtime to time, and shifting that contained in the fur nace along toward the rear and removing the residuum thereat, as described.

NATHAN BARTLETT.

Witnesses:

T. B. MOSHER, ALEX.` F. ROBERTS. 

